ble_gattc_write_no_rsp_flat error code 0x06

I am using Nimble 1.8.0. The Linux Central connects to 16 Perpetual development boards and exchanges simple data with them at a rate of once per second. After a while, the `ble_gattc_write_no_rsp_flat` function on the Central returns an error with error code 0x06. I encountered the same issue after switching to Nimble 1.10.0.

Start by tracing the Linux Central call to ble_gattc_write_no_rsp_flat and checking what error code 0x06 represents in Nimble 1.8.0 and 1.10.0. Reproduce the issue with the reported 16-board, once-per-second workload and document the conditions under which the function fails; the issue is not yet specific about a source file or test.

Written by the indexing model from the issue text.